Flu and gastro set to spread winter blues

Australia is headed for a flu season to rival 2012, as well as severe gastro outbreaks.

It's likely the Sydney 2012 gastro virus will return after spreading to Europe, the UK and US and causing a global pandemic, experts warn.

There could be major outbreaks of the bug, which causes nausea, vomiting and diarrhoea, University of NSW Professor Peter White told an Australian Science Media Centre briefing on Thursday.

Australia did not have a severe outbreak in 2012 and any new outbreak could have similar severity to an emerging new virus.

"We could see wards closed to new admissions as well as emergency department closures," said Prof White, the team leader of the research group that identified the new strain of pandemic norovirus Sydney 2012.

Prof White said the average infection rate for all forms of gastroenteritis in a developed country was one case per person per year.

Meanwhile, influenza expert Ian Barr told the briefing that predicting seasonal flu levels was tricky, but past seasons locally and overseas were a good guide.

The US had a severe season in 2012/13 and the 2012 season in Australia was moderate to severe.

In severe seasons hospital wards can be full, elective surgery can be cancelled and there can be large-scale absences from work, said Dr Barr, Deputy Director of the Australian World Health Organisation collaborating centre on influenza.

So far signs were that the season would mirror 2012, the second-worst on record, he said.

There had been 3379 lab-confirmed cases by May 28, slightly up from the same period in 2012.

It was not too late to be vaccinated before the season's start in July, Dr Barr said.

Flu is generally a mild disease but there can be severe consequences. At least 60 people, mostly elderly, died in 2012.

Nationally, 48 children aged under 15 were admitted to hospital, with 23 admitted to intensive care.

In Queensland, for example, there were 1603 hospitalisations and 157 people needed intensive care treatment, Dr Barr said.

There are four distinct flu viruses in humans, with the H1N1 making a comeback this year.

"If people are thinking about vaccination they should speak to their GP. It is not too late," Prof White said.

"If they don't want to be vaccinated, some of the things they should keep in mind are the use of influenza antivirals, which are available on prescription."

However, they are most effective when used within 48 hours of a person noticing symptoms.